[XEN][RFC PATCH v4 14/16] tools/libs/ctrl: Implement new xc interfaces for dt overlay

[Vikram Garhwal <vikram.garhwal@xxxxxxx>]

xc_dt_overlay() sends the device tree binary overlay, size of .dtbo and overlay
operation type i.e. add or remove to xen.

Signed-off-by: Vikram Garhwal <vikram.garhwal@xxxxxxx>
---
 tools/include/xenctrl.h         |  3 ++
 tools/libs/ctrl/Makefile.common |  1 +
 tools/libs/ctrl/xc_dt_overlay.c | 51 +++++++++++++++++++++++++++++++++
 3 files changed, 55 insertions(+)
 create mode 100644 tools/libs/ctrl/xc_dt_overlay.c

diff --git a/tools/include/xenctrl.h b/tools/include/xenctrl.h
index 0c8b4c3aa7..a71bc0bb1d 100644
--- a/tools/include/xenctrl.h
+++ b/tools/include/xenctrl.h
@@ -2633,6 +2633,9 @@ int xc_livepatch_replace(xc_interface *xch, char *name, 
uint32_t timeout, uint32
 int xc_domain_cacheflush(xc_interface *xch, uint32_t domid,
                          xen_pfn_t start_pfn, xen_pfn_t nr_pfns);
 
+int xc_dt_overlay(xc_interface *xch, void *overlay_fdt,
+                  uint32_t overlay_fdt_size, uint8_t overlay_op);
+
 /* Compat shims */
 #include "xenctrl_compat.h"
 
diff --git a/tools/libs/ctrl/Makefile.common b/tools/libs/ctrl/Makefile.common
index 0a09c28fd3..247afbe5f9 100644
--- a/tools/libs/ctrl/Makefile.common
+++ b/tools/libs/ctrl/Makefile.common
@@ -24,6 +24,7 @@ OBJS-y       += xc_hcall_buf.o
 OBJS-y       += xc_foreign_memory.o
 OBJS-y       += xc_kexec.o
 OBJS-y       += xc_resource.o
+OBJS-$(CONFIG_ARM)  += xc_dt_overlay.o
 OBJS-$(CONFIG_X86) += xc_psr.o
 OBJS-$(CONFIG_X86) += xc_pagetab.o
 OBJS-$(CONFIG_Linux) += xc_linux.o
diff --git a/tools/libs/ctrl/xc_dt_overlay.c b/tools/libs/ctrl/xc_dt_overlay.c
new file mode 100644
index 0000000000..325c9ef4c0
--- /dev/null
+++ b/tools/libs/ctrl/xc_dt_overlay.c
@@ -0,0 +1,51 @@
+/*
+ *
+ * Device Tree Overlay functions.
+ * Copyright (C) 2021 Xilinx Inc.
+ * Author Vikram Garhwal <fnu.vikram@xxxxxxxxxx>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "xc_bitops.h"
+#include "xc_private.h"
+#include <xen/hvm/hvm_op.h>
+#include <libfdt.h>
+
+int xc_dt_overlay(xc_interface *xch, void *overlay_fdt,
+                  uint32_t overlay_fdt_size, uint8_t overlay_op)
+{
+    int err;
+    DECLARE_SYSCTL;
+
+    DECLARE_HYPERCALL_BOUNCE(overlay_fdt, overlay_fdt_size,
+                             XC_HYPERCALL_BUFFER_BOUNCE_IN);
+
+    if ( (err = xc_hypercall_bounce_pre(xch, overlay_fdt)) )
+        goto err;
+
+    sysctl.cmd = XEN_SYSCTL_dt_overlay;
+    sysctl.u.dt_overlay.overlay_op = overlay_op;
+    sysctl.u.dt_overlay.overlay_fdt_size = overlay_fdt_size;
+
+    set_xen_guest_handle(sysctl.u.dt_overlay.overlay_fdt, overlay_fdt);
+
+    if ( (err = do_sysctl(xch, &sysctl)) != 0 )
+        PERROR("%s failed", __func__);
+
+err:
+    xc_hypercall_bounce_post(xch, overlay_fdt);
+
+    return err;
+}
-- 
2.17.1